Soothill (1934): "To behold the Buddha-nature within oneself, a common saying of the Chan (Zen) or Intuitive School."[15]

Fischer-Schreiber (1991): Lit. "seeing nature"; Zen expression for the experience of awakening (enlightenment). Since the meaning is "seeing one's own true nature," kenshō is usually translated "self-realization." Like all words that try to reduce the conceptually ungraspable experience of enlightenment to a concept, this one is also not entirely accurate and is even misleading, since the experience contains no duality of "seer" and "seen" because there is no "nature of self' as an object that is seen by a subject separate from it.[10]

Baroni (2002): "Seeing one's nature," that is, realizing one's own original Buddha Nature. In the Rinzai school, it most often refers more specifically to one's initial enlightenment attained though kōan practice.[1]

Muller (year unknown): To see one's own originally enlightened mind. To behold the Buddha-nature within oneself, a common saying of the Chan school, as seen for example, in the phrase 'seeing one's nature, becoming Buddha' 見性成佛.[14]

D.T. Suzuki: "Looking into one's nature or the opening of satori";[16] "This acquiring of a new point of view in our dealings with life and the world is popularly called by Japanese Zen students 'satori' (wu in Chinese). It is really another name for Enlightenment (Annuttara-samyak-sambodhi)".[17][note 4]

Dumoulin (1988/2005): "Enlightenment is described here as an insight into the identity of one's own nature with all of reality in an eternal now, as a vision that removes all distinctions. This enlightenment is the center and the goal of the Zen way. Hakuin prefers the term "seeing into one's nature", which for him means ultimate reality. The Buddha nature and the cosmic Buddha body, wisdom (prajna), and emptiness (sunyata), the original countenance one had before one was born, and other expressions from the rich palette of Mahayana terms were all familiair to him from his continued study of the sutras and Zen literature."[19]

G. Victor Sogen Hori (2000): "The term consists of two characters: ken, which means "see" or "seeing", and sho, which means "nature", "character", "quality." To "see one's nature" is the usual translation for kensho".[2]

The term kenshō refers to the realization of nonduality of subject and object in general,[23] but the term kenshō may also be applied in other contexts:[24] "How do you kenshō this?"[23]

Kenshō is not a single experience, but refers to a whole series of realizations from a beginner's shallow glimpse of the nature of mind, up to a vision of emptiness equivalent to the 'Path of Seeing' or to Buddhahood itself. In all of these, the same 'thing' is known, but in different degrees of clarity and profundity.[20][25]

"Kenshō" is commonly translated as enlightenment, a word that is also used to translate bodhi, prajna, satori and buddhahood. Western discourse tends to use these terms interchangeably, but there is a distinction between a first insight, and the further development toward Buddhahood.

Kensho is insight, an understanding of reality as-it-is.[26][20][19][23] Contemporary understanding also describes kensho as an experience, as in "enlightenment experience"; the term "enlightenment experience" is itself a tautology: "Kensho (enlightenment) is an enlightenment (kensho)-experience".

The notion of "experience" has been criticised.[39][43][44] Robert Sharf points out that "experience" is a typical western term, which has found its way into Asian religiosity via western influences.[39][note 7] The notion of "experience" introduces a false notion of duality between "experiencer" and "experienced", where-as the essence of kensho is the realisation of the "non-duality" of observer and observed.[23][26] "Pure experience" does not exist; all experience is mediated by intellectual and cognitive activity.[27][46] The specific teachings and practices of a specific tradition may even determine what "experience" someone has, which means that this "experience" is not the proof of the teaching, but a result of the teaching.[47] A pure consciousness without concepts, reached by "cleaning the doors of perception"[note 8], would be an overwhelming chaos of sensory input without coherence.[49] The notion of "experience" also over-emphasises kensho, as if it were the single goal of Zen-training, where-as the Zen-tradition clearly states that "the stink of Zen"[50] has to be removed and the "experience" of kensho has to be integrated into daily life.[51][4][8] In the Rinzai-school this post-satori training includes the study and mastering of great amounts of classical Chinese poetry, which is far from "universal" and culture-transcending. On the contrary, it demands an education in culture-specific language and behaviour, which is measured by specific and strict cultural norms.[52] Emphasising "experience" "reduces the sophisticated dialectic of Ch'an/Zen doctrine and praxis to a mere "means" or set of techniques intended to inculcate such experiences".[53]

The classical Zen-texts, such as the Kao-seng-chuan (Biographies of Eminent Monks) and the transmission lists, called "Transmission of the Lamp"[note 9] the yü-lü genre[57] (the recorded sayings of the masters, such as the Linji yü lü); and the various koan-collections,[note 10] contain accounts of "enlightenment experiences". These accounts are not verbatim recordings of such "experiences", but well-edited texts, written down decades or even decennia after the supposed sayings and meetings.[58]

The Denkōroku, "The Record of the Transmission of the Light", written by Keizan Jōkin 瑩山紹瑾 (1268–1325), is an example of the "Transmission of the Lamp"-genre. It contains literary accounts of the patriarchs of the Soto-lineage, from Shakyamuni Buddha to Koun Ejō, in which kensho plays a central role. They are not to be taken as literal accounts of awakening, but as stories underpinning the legitimicay of the Dogen-shu, which in its early history had seen a fierce internal conflict over the correct lineage during the Sandai sōron.[59][60][note 11]

The Denkoroku gives the following account of Dogen's awakening:

Once, during late-night zazen, Rujing told the monks, "Studying Zen is the dropping off of body and mind." Hearing this, the master was suddenly greatly awakened. He went at once to the Abbott's room and burned incense. Rujing asked him, "Why are you burning incense?" The master answered, "Body and mind have dropped off." Rujing said, "Body and mind have dropped off, the dropped-off body and mind." The master said, "This is a temporarily ability; you must not approve me without reason." Rujing replied, "I am not approving you without reason." The master asked, "Why are you not approving me without reason?" Rujing said, "You dropped off body and mind." The master bowed. Rujing said, "You have dropped off dropping off."[62]

Although the Zen tradition is reluctant to speak openly about the 'experience' of kensho,[63] personal accounts can be found in Zen-texts.

Hakuin gives this description of his first kensho, when he was 21:[64]

At around midnight on the seventh and final night of my practice, the boom of a bell from a distant temple reached my ears: suddenly, my my body and mind dropped completely away. I rose clear of even the finest dust. Overwhelmed with joy, I hollowed out at the tops of my lungs, "Old Yen-t'ou is alive and well! [...] After that, however, I became extremely proud and arrogant".[65]

Hakuin's kensho was not approved by Shoju Rojin, who subjected Hakuin to more koan-training. This resulted in a second kensho, where-after Hakuin left Shoju Rojin. It was only when he was 41 that he attained "his final great enlightenment":[64]

[W]hen Shoju had asked his reason for becoming a monk, his reply - that he had done it because he was afraid of falling into hell - had brought the scornful retort: "You're a self-centered rascal, aren't you!" Not until eighteen years later, upon attainment of his final great enlightenment at the age of forty-one, would Hakuin fully grasp the significance of Shoju's reproach and with it the true meaning of "post-satori" practice. Years later, when Hakuin asked his student Torei the same question, Torei's answer - "To work for the salvation of my fellow beings" - brought a laugh from Hakuin. "A much better reason than mine", he said.[64]

Keido Fukushima, a 20th-century Rinzai abbott, gives the following description:

At Nanzenji there is a small hill. I used to walk near there, look at it, and often smile at the high school students who walked by there as well. One day as I walked by, I looked at the hill and it was truly amazing. i was totally lost as if there was no 'me'. I stood gazing at the hill. Some students walked by and one of them said something like 'look at that crazy monk'. Finally I came out of it. Life was never the same for me. I was free.[63][note 12]

Kenshō may be attained without the aid of a teacher. For example, Richard Clarke (1933), who studied with Philip Kapleau, states that he had a spontaneous kensho when he was 13.[web 2]Dennis Genpo Merzel states he had what he described as an "awakening experience" in 1971:[web 3]

It was in February of that year, and I was 26 years old. My second serious relationship was ending, and I was feeling very confined and conflicted. I needed to get some space, so I went out to the Mojave desert for a three-day camping weekend with two friends. On the Friday, I hiked up a mountain alone. I knew nothing about meditation or spiritual practice. I was just sitting there, thinking about my life and the things going on. I felt I had gotten pretty screwed up for such a young age.

I could see my VW camper, my home for the weekend, parked a few miles away, . But at the same time, I was aware that my home was back in Long Beach, California. And a natural koan came to me: Where is home? All of a sudden, I had a kind of breakthrough. I felt myself fall away, and I became one with the cosmos, one with the universe, one with all things. I knew in that moment that wherever I am, that is home; home is everywhere. I also knew who I was, beyond description, but let’s call it Big Mind.
That experience completely changed my life.[web 3]

More descriptions of "spontaneous kensho" can be found throughout the Zen-literature,[note 14] while a classic example may be Ramana Maharshi's awakening.

According to Harris, working towards kensho is usually a lengthy process stretched out over years or even decades.[74] Contrary to this, Victor Hori notes that with koan-study kensho may appear within six months. [75][note 15]

Sōtō tends towards a gradual approach, preferring to let the experiences happen on their own. Rinzai tends toward the use of Koans as a technique to unroot the habitual workings of the mind.[78]

During intensive zazen various hallucinations and psychological disturbances may arise. These are referred to as makyo. Distinguishing these delusions from actual kensho is the primary function of the teacher, as the student may be erroneously convinced they have realized kensho.

At some point in time we pass from imprisonment in ignorance and delusion to a true vision of Zen realization: "Our enlightenment is timeless, yet our realization of it occurs in time." According to this belief experiencing a moment of awakening in this life is of central importance.[79]

In the Rinzai-training, the student is expected to pour oneself totally in both koan-study and daily activities 'to become one' with it.[24] Kenshō is used to describe the first breakthrough in kōan study.[1][note 16]

In the Sōtō school there are two kinds of awakening.[80] One is the practice of shikantaza, which is the "actual enlightened activity of the Buddha".[80] The other is the accumulation of little bits of understanding, which come together, giving way to a deeper intuitive knowledge.[81]

The "genjo-koan", or the "koan of everyday life" which "appears naturally in daily life",[82] is emphasized. Students are not encouraged to actively seek out kenshō experiences. In Sōtō practice kenshōs "are allowed to occur naturally, as a by-product of practice. Meditative training is seen as the unfolding of one great kenshō:[20]

According to the tradition of Soto Zen, although working on a koan is one way of attaining kensho, the best way is zazen. Indeed, Dogen, the founder of Soto Zen, expounded that zazen itself is enlightenment, and as long as the adept maintains a pure state of non-thinking in Zen, he is a Buddha.[83]

Kenshō also plays a central in the Sanbō Kyōdan, a Japanese Zen-organisation which played a decisive role in the transmission of Zen to the United States.[42] Yasutani, the founder of the Sanbo Kyodan, was disappointed about the lack of interest in kensho in the Soto-school. Yasutani's emphasis on koan-training and the importance of kensho was transmitted to his American students:[42]

He was especially vocal concerning the point of kenshō, seeing one's true nature. He spoke more openly about it then anyone of his times, going so far as to have a public acknowledgement of those who had experienced kensho in a post-sesshin ceremony of bowing in gratitude to the three treasures.[84]

It is also reflected in the inclusion of a relative great amount of kensho-stories in "The three pillars of Zen", written by Philip Kapleau, a student of Yasutani.[4]

Zen Buddhist training does not end with kenshō. Practice is to be continued to deepen the insight and to express it in daily life.[51][4][8][85] According to the contemporary Chan Master Sheng Yen:

Ch'an expressions refer to enlightenment as "seeing your self-nature". But even this is not enough. After seeing your self-nature, you need to deepen your experience even further and bring it into maturation. You should have enlightenment experience again and again and support them with continuous practice. Even though Ch'an says that at the time of enlightenment, your outlook is the same as of the Buddha, you are not yet a full Buddha.[7]

And the contemporary western Rev. Master Jiyu-Kennett:

One can easily get the impression that realization, kenshō, an experience of enlightenment, or however you wish to phrase it, is the end of Zen training. It is not. It is, rather, a new beginning, an entrance into a more mature phase of Buddhist training. To take it as an ending, and to "dine out" on such an experience without doing the training that will deepen and extend it, is one of the greatest tragedies of which I know. There must be continuous development, otherwise you will be as a wooden statue sitting upon a plinth to be dusted, and the life of Buddha will not increase.[86]

Post-awakening practice is called seitai choyo, the "long nurturing of the sacred fetus".[89][note 17] According to Spiegelberg,

[I]t means a return to the purely secular life, a complete submersion in work and in the changing events of the world. Thus, for decades, many Zenists, after their awakening, went among the people, living among beggars and leading an existence of hard physical labor. Thus it was proved whether or not the truth received was of permanent value, or whether it would vanish among mundane affairs.[91]

During the T'ang-era, the term became associated with the ideal of the recluse who leaves the world.[92] An ideal period of "twenty years" was taken for it, echoing a story from the Lotus Sutra about a prodigal son who wandered in poverty for twenty years before returning home.[93] References to these twenty years are found throughout the Chán-tradition, for example Linji, who is reported to have studied under Huang-po for twenty years,[93] and Daito, the founder of Daitoku-ji, who famoulsy spent twenty years living under a bridge with beggars.[93]

Post-satori practice for Hakuin meant finally ceasing to be preoccupied with his own personal condition and attainment and to devote himself and his practice to helping and teaching others. Finally, at long last, he realized that true enlightenment is a matter of endless practice and compassionate functioning, not something that occurs once and for all in one great moment on the cushion.[web 4][note 19]

Kensho does not eradicate our unhealthy habits [...] There is a sudden awakening to the fact of "no-self" and then this insight has to be integrated into one's life which means that it has to be embodied and not just be a memory.[web 5]

And "experience" has to be supplemented by intellectual understanding and study of the Buddhist teachings;[106][107][108] otherwise one remains a zen temma, a "Zen devil".[109] Finally, these efforts are to result in a natural, effortless, down-to-earth state of being, the "ultimate liberation", "knowing without any kind of defilement".[110]

Kenshō is described as appearing suddenly, upon an interaction with someone else, at hearing or reading some significant phrase, or at the perceiving of an unexpected sound or sight.[111] The idea of "sudden insight" has been hotly debated in the history of Zen. It became part of the Traditional Zen Narrative in the 8th century.[112]

Chinul, a 12th-century Korean Seon master, emphasized that insight into our true nature is sudden, but is to be followed by practice to ripen the insight and attain full Buddhahood. The contemporary Korean Seon master Seongcheol opposed this, emphasizing "sudden enlightenment, sudden cultivation". But Jiyu-Kennett, a contemporary western teacher, warns that attaining kenshō does not mean that a person is free from morality, the laws of karma, or the consequences of ones actions.[113] This warning is reflected in the Wild fox koan.

Though the literal meaning is self-awakened, or awakened on one's own, the emphasis in Zen, when using these terms, lies in the ultimate reliance on one's own insight, instead of the authority of a teacher:

It is awakening that is one's true master. With Shakyamuni, the awakening was his master. In other words, the awakened self is one's master. Apart from getting awakened to that master, there is no awakening. Here practitioner and master are of one body, not two. Instead of having another verify or confirm one's awakening, one does so for oneself. Of course in this case the self that is verified and the master who does verification are undivided. In their being completely identical is the autonomous, independent, or ultimate nature of the authenticity.[web 7]

The Dzogchen-traditions states that the ultimate nature of all sentient beings is pure, all-encompassing, primordial awareness, or naturally occurring timeless awareness. This intrinsic awareness has no form of its own, and yet is capable of perceiving, experiencing, reflecting, or expressing all form. It does so without being affected by those forms in any ultimate, permanent way.

The analogy given by Dzogchen masters is that one's nature is like a mirror which reflects with complete openness, but is not affected by the reflections. Rigpa is the knowledge that ensues from recognizing this mirror-like clarity,[117] which cannot be found by searching nor identified.[118] One knows that there is a primordial freedom from grasping his or her mind.[119]

In Advaita Vedanta moksha is attained by jnana, insight-knowledge. In Shankara's philosophical synthesis insight samadhi is used as a subsidiary to this goal. Swami Vivekananda emphasized the experience of nirvikalpa samadhi as a means to validate religious, transcendental knowledge.[120]

^According to Fischer-Schreiber, kenshō and satori are nearly synonymous, with a customary distinction of using kenshō for an initial enlightenment experience that still requires deepening, and satori for the Buddhahood enlightenment of a Buddha or Zen patriarch.[10] Hakuin uses the word "satori" for initial insight, synonymous with kensho.[11]

^The Japanese Zen-tradition has a rich vocabulaire of terms related to "enlightenment": awakenening (kaku), true awakening (shōgaku), perfect awakening (engaku), insight (sei), attaining the Way (jōdō), becoming Buddha (jōbutsu), opening the eye (kaigen), liberation (gedatsu), aythetication (shō), the great death (daishi), self-enlightenment without a teacher (mushi dokugo), great satori with full penetration (taigo tettei), and peerless perfect enlightenment (anokutara sanmyaku sanbodai).[12] The list is not exhausted with these terms.[12] Another term for deep awakening is daigo.

^D.T. Suzuki has been ctiticised for his highly idealised and inaccurate picture of Japanese Zen.[18]Annuttara-samyak-sambodhi is the highest state of realisation and awakening. Satori, or kensho, is a first glimpse into "nature", to be followed by further training.

^Victor Sogen Hori notes that Nishida Kitaro, although using a western terminology, tried to express basic Mahayana Teachings: "He borrowed, for example, the term, junsui keiken, "pure experience", from William James, but then went on to say that, while for James the individual preceded pure experience, for him, pure experience preceded the individual. That reversal makes Nishida’s notion of pure experience resemble less the psychology of William James and more the Mahayana notion of sunyata.[29]

^James also gives descriptions of conversion experiences. The Christian model of dramatic conversions, based on the role-model of Paul's conversion, may also have served as a model for western interpretations and expectations regarding kensho, similar to Protestant influences on Theravada Buddhism, as described by Carrithers: "It rests upon the notion of the primacy of religious experiences, preferably spectacular ones, as the origin and legitimization of religious action. But this presupposition has a natural home, not in Buddhism, but in Christian and especially Protestant Christian movements which prescribe a radical conversion."[31] See Sekida for an example of this influence of William James and Christian conversion stories, mentioning Luther[32] and St. Paul.[33] See also McMahan for the influence of Christian thought on Buddhism.[34]

^Robert Sharf: "[T]he role of experience in the history of Buddhism has been greatly exaggerated in contemporary scholarship. Both historical and ethnographic evidence suggests that the privileging of experience may well be traced to certain twentieth-century reform movements, notably those that urge a return to zazen or vipassana meditation, and these reforms were profoundly influenced by religious developments in the west [...] While some adepts may indeed experience "altered states" in the course of their training, critical analysis shows that such states do not constitute the reference pont for the elaborate Buddhist discourse pertaining to the "path".[45]

^William Blake: "If the doors of perception were cleansed every thing would appear to man as it is, infinite. For man has closed himself up, till he sees all things thru' narrow chinks of his cavern."[48]

^A literary device to establish a lineage. Both T'ien Tai and Chán took over this literary device, to lend authority to those developing traditions, and guarantee its authenticity.[54][55] Notable examples are the Anthology of the Patriarchal Hall (952) and the Jingde Records of the Transmission of the Lamp (published 1004). McRae considers Dumoulin's A History of Zen to be a modern example of this genre, disguished as scientific history;[56]

^The two best known koan-collections (in the west) are the "Gateless Gate" and the "Blue Cliff Record". The Gateless Gate (Chinese: 無門關 Wumenguan; Japanese: Mumonkan) is a collection of 48 kōans and commentaries published in 1228 by Chinese monk Wumen (無門) (1183–1260). The title may be more accurately rendered as Gateless Barrier or Gateless Checkpoint. The Blue Cliff Record (Chinese: 碧巖錄 Bìyán Lù; Japanese: Hekiganroku) is a collection of 100 kōans compiled in 1125 by Yuanwu Keqin (圜悟克勤 1063–1135).

^Cook: "It is probably safe to say that few if any reputable modern scholars, and probably not many even within the Soto priesthood itself, believe that many of the central events and characters in the Denkoroku are based on historical fact [...] The origins and early developments of Chinese Zen are just now becoming clearer, and the gradually emerging picture is very different from the traditional Zen history found in such works as Keizan's record".[61]

^Harris: "After this experience Gensho still had two more years of koan study".[63]

^Kapleau gives ten different accounts of contemporary practitioners, including his own kensho under the initials "KP".[4] Sekida gives an elaborate account of his own kenshos,[66] and gives various accounts of others.[67] Satomi gives an account of becoming one with the mu-koan, the classical aimed kensho of the Sanbo Kyodan.[68] Maura O'Halloran also gives an account of herself becoming mu.[69]

^Sekida gives the example of a woman, who's "strong internal pressure (gidan) never stopped knocking from within at the door of her mind, demanding to be resolved [...] One day, when she was about to take a bath, a certain change occurred in her. Although this was later confirmed as kensho by a teacher, she had no idea what it was.[70] Philip Kapleau describes a man who had kensho, which was explained as a "conversion experience" by psychiatrists.[71] Flora Courtois gives an extensive account of her spontaneous kensho,[72] on which Yasutani comments.[73]

^Houn Jiyu-Kennett, a western sei-kyoshi[76] or soto-priest, also is reported to have attained kensho after six months of tarining in a Soto-monastery.[77]

^According to Kraft, one of the earliest expressions of this term is found in a 5th-century Chinese translation of the Prajnaparamitra Sutra on Benevolent Kings Protecting Their Countries.[90] In Chán-texts the term is first used by Mazu (709-788), and in Japan it was introduced by Dogen who learned it from his teacher T'ien t'ung Ju-ching (1163-1228).[90] See also Muso Soseki, Dialogues in a Dream translation, translated by Thomas Yuho Kirchner, for its meaning and application.